The present invention relates to a seat valve for the control of pneumatic or hydraulic pressure between at least two pressure fluid channels.
German patent application No. 40 30 571 discloses an electromagnetic seat valve, closed in its de-energized condition, for the control of hydraulic pressure, which includes a magnetic armature to which a valve closure member is attached, and a spring that urges a valve closure member against a valve seat by a defined preload. The valve seat is mounted in the valve housing. Further, a magnetic core is accommodated in a thin-walled valve sleeve and a valve coil is secured to the valve sleeve. The winding of the valve coil is configured so that the magnetic armature performs exclusively a translatory movement so that the valve closure member is either opened or closed stroke-responsively as a function of the electromagnetic energization of the valve coil. This produces a binary switching behavior with relatively quick stroke movements. However, a variable adjustment of the rate of fluid flow is not permitted thereby.
An object of the present invention is to improve a seat valve of the type mentioned hereinabove by simple and functionally reliable means to such effect that in addition to the actual translatory movement of the valve closure member the rate of fluid flow can be adjusted variably with minimum possible electric energy demand.